As a result of economic and packaging objectives and other needs and requirements for more compact, electrical and electronic components and their interconnections and accompanying greater miniaturization thereof, manufacturers are required to deliver products that have more efficient and effective use of the space and real estate on the surfaces of circuit cards, substrates, circuit boards and the like. The various elements and components making up the circuit product are required to be positioned in greater density and with minimal spacing therebetween. Proper aligning of leads and connections among the components and to terminals on substrates, for example, is becoming more difficult and increasingly critical. These products, components, and their interconnections must be visually inspected before final packaging, encapsulation and incorporating into finished products with the objective of eliminating expensive and inefficient product defects and resultant recalls. Thus, routine visual inspections are performed at various stages in the manufacture of a product by making use of examination by tools such as microscopes. As the degree of miniaturization increases, more powerful microscopes are required in order to effectively carry out these visual inspections. As microscopes of greater power and magnification are required, these microscopes are becoming necessarily larger and heavier in design. As a result, problems caused by vibration of the microscope and its mounting stand and the proper orientation of the microscope become significant in order to provide correct and accurate inspection of these manufactured products. A more sturdy and robust stand than is presently available is needed.
Undesirable vibrations arise from a variety of sources which affect the use of devices mounted on stands, including vibrations resulting from normal manual adjustments, the movement resulting from the shutter of a camera, from the dynamics of microscope accessories, or simply from an operator touching the microscope superstructure. Many previous attempts to deal with vibration problems in microscopes have centered around the isolation of the microscope from its environment by the use of shock mountings. External mechanical vibrations obviously have disturbing effects on the quality of the image resulting from use of a microscope or camera.
Previous efforts have been made in attempts to design stands for the effective mounting of microscopes. While existing stand designs may have certain advantages, these prior designs have not been found to be adequate for present purposes and particularly for those purposes in situations as described above.
One such design is described in U.S. Pat. No. 4,168,881, entitled “Anti-Vibration Microscope Stand”, which issued Sep. 25, 1979 to Rosenberger. The description provided in this patent assumes that the most critical relationship in a microscope as inherent vibrations are concerned is the relative positioning of the object lens and the specimen plane. The eye piece and the object lens are separately mounted. The object lens is mounted in a cantilever manner which is rigidly attached to a support pillar. The eye piece is also cantilevered from the support pillar and is free of contact with the object lens except from the remote contact with the pillar. The design is such that vibrations emanating from the eye piece area are absorbed and the eye piece support is isolated from the specimen plane and the object lens mounting member.
Another example is described in U.S. Pat. No. 5,127,614, entitled, “Microscope Stand”, which issued Jul. 7, 1997 to Etzold et al. This patent describes a microscope stand consisting of a base, a column, a tubular holder and feet in which a greater level of insensitivity to vibration may be achieved.
Another example of a stand is provided in U.S. Pat. No. 4,742,947, entitled “Optical System For Use As Stand Alone Unit Or With A Device For Attaching Modular Electronic Components To Or Removing Them From A Substrate”, which issued May 10, 1988 to Coffman et al. A microscope stand is described which permits a microscope to be horizontally rotated from +90° to −90° and vertically rotated through 90° so as to provide complete viewing of an object.